Abstract

The efficacy of a sound localization training procedure that provided listeners with auditory, visual, and proprioceptive/vestibular feedback as to the correct sound-source position was evaluated using a virtual auditory display that used nonindividualized head-related transfer functions (HRTFs). Under these degraded stimulus conditions, in which the monaural spectral cues to sound-source direction were inappropriate, localization accuracy was initially poor with frequent front-back reversals (source localized to the incorrect front-back hemifield) for five of six listeners. Short periods of training (two sessions) were found to significantly reduce the rate of front-back reversal responses for four of five listeners that showed high initial reversal rates. Reversal rates remained unchanged for all listeners in a control group that did not participate in the training procedure. Because analyses of the HRTFs used in the display demonstrated a simple and robust front-back cue related to energy in the bandwidth, it is suggested that the reductions observed in reversal rates following the training procedure resulted from improved processing of this front-back cue, which is perhaps a form of rapid perceptual recalibration. Reversal rate reductions were found to generalize to untrained source locations, and persisted at least following the training procedure.

The authors thank Dr. Fred Wightman and Dr. Doris Kistler for providing HRTF comparison data for listener SLO, and Dr. Armin Kohlrausch, Dr. Nathaniel I. Durlach, and two anonymous reviewers for their comments on earlier versions of this work. Financial support was provided under the Federated Laboratory Program by the U.S. Army Research Laboratory, Cooperative Agreement DAAL01-96-2-0003, and by NIH-NEI (F32EY07010) and NIH-NIDCD (R03DC005709).